[jira] [Resolved] (HDFS-11179) LightWeightHashSet can't remove blocks correctly which have a large number blockId

["Takanobu Asanuma (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HDFS-11179?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Takanobu Asanuma resolved HDFS-11179.
-------------------------------------
          Resolution: Invalid
    Target Version/s:   (was: 3.0.0-alpha2)

> LightWeightHashSet can't remove blocks correctly which have a large number blockId
> ----------------------------------------------------------------------------------
>
>                 Key: HDFS-11179
>                 URL: https://issues.apache.org/jira/browse/HDFS-11179
>             Project: Hadoop HDFS
>          Issue Type: Bug
>          Components: namenode
>    Affects Versions: 3.0.0-alpha1
>            Reporter: Takanobu Asanuma
>            Assignee: Takanobu Asanuma
>
> Our test cluster has faced a problem that {{postponedMisreplicatedBlocksCount}} has been going below zero. The version of the cluster is a recent 3.0. We haven't created any EC files yet. This is the NN's log:
> {noformat}
> Rescan of postponedMisreplicatedBlocks completed in 13 msecs. 448 blocks are left. 176 blocks are removed.
> Rescan of postponedMisreplicatedBlocks completed in 13 msecs. 272 blocks are left. 176 blocks are removed.
> Rescan of postponedMisreplicatedBlocks completed in 14 msecs. 96 blocks are left. 176 blocks are removed.
> Rescan of postponedMisreplicatedBlocks completed in 327 msecs. -77 blocks are left. 177 blocks are removed.
> Rescan of postponedMisreplicatedBlocks completed in 15 msecs. -253 blocks are left. 179 blocks are removed.
> Rescan of postponedMisreplicatedBlocks completed in 14 msecs. -432 blocks are left. 179 blocks are removed.
> {noformat}
> I looked into this issue and found that it is caused by {{LightWeightHashSet}} which is used for {{postponedMisreplicatedBlocks}} recently. When {{LightWeightHashSet}} remove blocks which have a large number blockId, overflows happen and the blocks can't be removed correctly(, let alone ec blocks whose blockId starts with the minimum of long).



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

---------------------------------------------------------------------
To unsubscribe, e-mail: hdfs-dev-unsubscribe@hadoop.apache.org
For additional commands, e-mail: hdfs-dev-help@hadoop.apache.org